Method of forming rings for bearings



Oct. 14, 1952 1 J, DIERBECK 2,613,429

METHOD OF' FORMING RINGS FOR vBEARTNGS Filed May 5, 1947 5 Sheets-Sheetl @l www 2 lai/- Oct. 14, 1952 J. J. DIERBECK 2,613,429

METHOD 0F FORMING RNGS FOR BEARINGS Filed May 5, 1947 5 Sl'uaets-Sheeil2 E@ 7 l5) 57K@ Oct. 14, 1952 J. J. DIERBECK METHOD OF' FORMING RINGSFOR BEARINGS 5 Sheets-Sheet 5 Filed May 3, 1947 Patented Oct. 14, A 1952METHOD OF FORM BEARIN ING RINGS FOR John J. Dierbeck, Milwaukee, Wis.,assignor to International Harvester Company, a corpora-Y tion of NewJersey Application MayV 3, 1947, Serial No. 745,778

1 Claim.

This invention relates to a, method especially adapted to themanufacture of races for roller bearings and for members of a similarshape. More specifically, it relates to a forming method for bearingraces in which the metal is worked in such a way as to obtain the mostdesirable grain `structure in the final article.

In the manufacture of races for bearings, such as tapered rollerbearings, various methods have been followed to form such members out ofrolled steel, which is a required metal in order to obtain a bearinghaving the desired strength and heating characteristics. As said membersare ring shaped, serious problems have been encountered in forming themfrom rolled steel to obtain the desired grain flow in the finished ringand to avoid excessive scrap material.

The principal object of the present invention is to provide a method ofmanufacturing bearing races from bar stock without the loss of anysubstantial amount of material as scrap and to so form the annular racemember that maximum density of grain structure is obtained at theWearing surface of the bearing member.

The above object and others which will be apparent wfrom the descriptionto `follow are obtained by a method as will be described in thespecification. As a means of illustrating how the method can bepracticed, the drawings show diagrammatically different steps in apreferred method.

In the drawings:

Figure lis a plan view of a section of cylindrical stock used for makingbearing races according' to the method of the invention.

Figure 2 is a plan View of the element shown in Figure 1.

Figure 3 is a diagrammatic view of dies and their relationship to ablank being preformed for a subsequent operation.

Figure 4 is a view similar to Figure 3 showing a further step in theinitial formation of a blank for forming bearing races.

Figure 5 illustrates another step in which the lblank is further actedupon in a subsequent opn Ving step, the beginning of which is shown inFigure 7.

Figure 9 shows the final operation of operating upon the blank producedby the operation illustrated in Figure 8.

Figure 10 is an enlarged section illustrating the final graindisposition in the completed bearing race.

As shown in Figures 1 and 2 of the drawings, the manufacture of bearingraces according to the invention starts with a cylindrical blank Bhaving a length substantially longer than its diameter. Said blank maybe shearedv or sawed from bar stock by any suitable means Without anysubstantial loss of material as scrap.

The blank B of Figure 1 is placed between dies designated in theirentirety by the reference characters lil and Il. The lower die isprovided with a recess I2 formed by a flat bottom surface I3 and aconical wall I4 extending outwardly and upwardly from the bottom wallI3. The upper die II is provided with a recess I5 formed by a datsurface I6 and a conical wall I1 extending downwardly and outwardly fromthe bottom surface IG. An annular surface I8 surround-s ing the die I0adjacent the conical wall i4 is adapted to abut a similar annularsurface I9 formed on the die member II adjacent the conical wall il.

In the forging or forming step illustrated in Figure 3 the blank B isheated, as this operation is performed with the blank in a heatedcondition. After the dies have come together as illustrated in Figure 3,the blank B has been altered in shape as designed by B1 in Figure 3. Ifthe blank B is originally cut from rolled bar stock, the grain flow isin parallel lines of the blank. With an operation as illustrated inFigure 3, the lines of grain iiow are bulged as illustrated by the linesin Figure 3. rfests made by micro-photographs of etched samples showclearly the grain structure as illustrated in Figure 3.

As a further operation, after the step illustrated in Figure 3, a,similar operation may be followed as shown in Figure 4, furtherflattening the blank in an axial direction. In some instances it may besatisfactory to ilatten the blank from its original shape as shown inFigure l directly to the shape shown in Figure 4, which will be referredto as B2. The dies in Figure i are very similar to Figure 3, an upperdie 20 and a lower die 2l being illustrated. The lower die 2| isprovided with a fiat bottom surface 22 and a conical outwardly andupwardly extending Wall 23 joining the bottom portion and an annularabutting portion 24 formed on the upper surface of the die. The surface22 and the wall 23 form a recess 25. The upper die is provided with arecess 26 formed by a fiat surface 27 and a conical wall 28 whichterminates adjacent an annular abutment surface 29. It will be notedthat in Figures 3 and 4 there is space left after the two dies havelcome together, resulting in ya rounded shape to the blank being formedand eliminating any flash or die marks at the central peripheral portionof the blank..

Figure shows in sequence the next step in applicants method by which abearing race is formed. The blank B2 from Figure 4, or a similar blank,is placed between two dies 30 and 3i as diagrammatically illustrated inFigure 5. The lower die 30 is provided with an annular recess 32, whichhas a at annular bottom wall 33. a slightly conical inner wall 34 formedby a central upward projection 35, and a curved outer Wall 36 whichterminates adjacent an annular upper surface 31 formed on the die 30.

The upper die 3l is formed with a recess 38 which is identical in shapeand size to the recess 32. Said recess is formed by an annular flatsurface 39, a slightly tapered inner surface t8 which is the wall of acentral projection fil, and a curved outer surface ft2 terminatingadjacent an annular surface 43 formed on the die Si around the recess38.

Figure 5 illustrates a completion of the forining operation. It will benoted that the surfaces 31 and 43 are spaced somewhat apart and that aforging flash or iin 44 projects outwardly from the blank, which at thisstep will be designated as B3. It will also be noted that theprojections and 4I are spaced apart, leaving a relatively thin web 45.

In Figure 6 mating dies are illustrated for removing the iin 44 and thecentral web 45. A lower die i6 has an outside cylindrical wall ll' ofthe diameter of the blank and a central opening iii of the diameter ofthe final inside diameter of the blank. An upper die 49 is provided withan annular recess formed by a substantially cylindrical centerprojection 5|, an annular surface 52 at the bottom of the recess, and asubstantially cylindrical surface 53 forming the outer wall of therecess. It is to be understood that a slight draft can be provided byslight tapering of the surface 53 and the surfaces of the projection 5lin order to withdraw the sheared blank from the dies. The dotted lineson the blank B3 in Figure 6 indicate the shear lines.

Figure '7 illustrates the blank designated as B4 obtained from theoperation performed by the structure shown in Figure 6. Said blank isplaced in a die 54 having a cylindrical bore 55, the conical wall 56joining said bore, a cylindrical wall portion 5l' correspondinggenerally to the outer surface of .the blank B4, and a curved portion 5Sjoining the top of the conical portion 56 and the bottom of the wall 5?.The blank B4 as illustrated lays on the portion 58.

A forming punch 59, the lower tapered portion '50, Which is shown inFigure 7, is of a sufficiently reduced shape to engage the centralopening in the blank B4.

Figure 8 shows the remainder of the die 5@ after the operation, thebeginning of which was illustrated in Figure 7, is completed. Said die,in addition to the tapered lower portion Si), includes a further curveddiverging portion 5i which is joined with the main portion 62 of thedie. It will be noted that the portion 6| has a reversed curve withrespect to the portion to better shape and form the interior surface ofthe blank being operated upon which will be designated in a form shownin Figure 8 by the reference character B5.

Figure 9 shows the nal step in applicants method of forming a bearingrace. The dotted lines of Figure 9 illustrate the blank B5 obtained fromthe operation illustrated in Figure 8. A lower die 63 is formed with acentral cylindrical bore 64, a stepped shoulder 65, and an uppercylindrical bore 66. The blank B5 is adapted to rest on the shoulder 65at the beginning of the forming operation.

An upper die 6l' is provided with a conical forming portion 68 which isadapted at its lower end to nt within the blank B5 as illustrated indotted lines at the beginning of the forming operation. The conicalshape of the blank B5 is then inverted so that the inside conical angleis in the opposite direction as evident by the final form of the blankwhich is designated as B6. The final blank B(i Very closely approximatesthe final shape and dimensions of the bearing race, with the result thatit is necessary to remove a minimum of material to provide the iinishedbearing race.

Throughout the drawings, lines have been shown in the successive stagesof the formation of the blank to illustrate the change in the grainstructure of the material. This is particularly significant, as byapplicants method there is a compacting of the material without anyappreciable disruption of the grain flow with the result that the iinalgrain structure as illustrated in the large section of Figure 10 isuniform and in the direction of the Wearing face 69 of the bearing race.This is the most desirable type of wearing surface and at the same timemaximum strength is obtained in the bearing race. With the grain flowresulting in a grain structure as illustrated in Figure 10, machiningand iinishing operations have a minimum eifect upon setting updisruption or in any way varying the uniform cross sectional strength ofthe bearing race. Such a grain structure is also very adaptable tohardening without setting up disrupting strains in the material.

The bearing race manufacturing method as above set forth lends itself toinduction heating as the small original cylindrical blanks can be evenlyand quickly heated by a high frequency induction coil of the type now inextensive use. The short heating period reduces sealing due to oxidationto a minimum as compared to previous methods of heating bar stock in gasor oil fired furnaces and upsetting the heated ends to provide thestarting blank.

It is to be understood that applicant has made only one preferreddisclosure of dies by which his improved method of forming bearing racesmay be practiced, and that he claims as his invention all modicationsfalling Within the scope of the appended claim.

What is claimed is:

A method of forming a bearing race for tapered roller bearings, whichmethod includes compressing a relatively long circular blank having agrain flow extending axially of the blank into a fiat circular slug ofgreater width than the initial blank, compressing'the slug furtherbetween a pair of substantially closed dies having centrally located andoppositely disposed projecting portions and oppositely disposed annularrecesses extending circumferentially of the projecting portions, thecompression forming a circular member having a greater width and beingthinner in cross section than the slug, said projecting portions forminga thin centrally disposed recessed web in said circular member. punchingout the web to form an opening. placing saidr circular member betweensecond dies to form it into an annular element in the form of a segmentof a cone, removing said segment from the second dies and placing saidsegment into third dies in a reversed position with respect to theposition of the segment in the second dies, and operating on the segmentof the cone with said second dies to increase the diameter of thesegment at its smaller end to the same diameter as the outer diameter ofthe other end and reversing the angle of the interior wall of thesegment.

JOHN J. DIE'RBECK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

